Manually controlled electric time switch



Aug. 27, 1968 D; E. THOMAS 3,399,283

MANUALLY CONTROLLED ELECTRIC TIME SWITCH Filed Oct. 27, 1965 5 Sheets-Sheet 1 5 3 57 //VVE A/7'Ok Fawn fiiz's fin/7M5 M l/ r W ATTORNEYJ Aug. 27, 1968 D. E. THOMAS MANUALLY CONTROLLED ELECTRIC TIME SWITCH 3 Sheets-Sheet 2 Filed Oct. 27, 1965 //Vl/NTOR [700M F/Zzli fiamaa g% Y /m ATTORNIE)! Aug. 27, 1968 n. E. THOMAS MANUALLY CONTROLLED ELECTRIC TIME SWITCH 5 Sheets-Sheet 3 Filed Oct. 2'7, 1965 United States Patent 3,399,283 MANUALLY CONTROLLED ELECTRIC TIME SWITCH David E. Thomas, Enfield, Middlesex, England, assignor to Sangamo Electric Company, Springfield, Ill., a corporation of Delaware Filed Oct. 27, 1965, Ser. No. 513,614 Claims priority, application Great Britain, Oct. 29, 1964, 44,204/64 Claims. (Cl. 20039) ABSTRACT OF THE DISCLOSURE A device for effecting operation of a switch means to first and second switching positions in time relation, including a pair of rotatable toothed discs adapted to be selectively alternatively coupled to rotating pawls in a manner to cause movement of the discs to effect the first and second switching positions.

This invention relates to electric time switches and is more particularly concerned with an improved, simplified and easily fabricated construction of such mechanisms.

Objects of this invention include the provision of a device in which the adjustable time setting abutments or targets are assembled in a time scale which at all times remains stationary thereby allowing the use of a time scale which is easily read and is logical in appearance, the provision of a structure which is of small axial depth suitable for forming a device of attractive appearance and adaptable for either wall or desk or table mounting and the provision of a device which provides for a plurality of on-off switching cycles in each unit, e.g. 24-hour, time period.

According to the invention there is provided an electric time switch in which the mechanical movements to effect operation thereof first to one switching position, e.g. the on or closed circuit condition and subsequently to a second switching position, e.g. the off or open circuit condition are derived respectively from a limited rocking of one and other of two spring-biased toothed discs caused by temporarily coupling first one and then the other of the latter to an associated one of two continuously rotating pawls brought about by the engagement of such pawls with abutments at chosen positions along the paths of movement of such pawls.

Preferably the fixed position abutments for engaging the respective, e.g. on or off pawls are in the form of adjustable position target pins readily insertable in and removable from a series of equi-space'cl holes in a fixed dial plate, the two series of holes being arranged as concentric circles. In a particular form the disc operated by the first or on pawl is arranged to operate the switch to one of two alternative switching positions through a switch controlling lever arm which becomes latched-in by a latch lever and the disc operated by the second or off pawl is arranged to trip such latch lever to release such switch controlling lever arm thereby causing return of the switch to its other switching position.

The device preferably also includes a manual over-ride control which is operative by movement in one sense also to move said switch operating lever arm to operate and latch the switch and by movement in an opposite sense to trip said latch lever to release the switch.

In order that the invention may be more readily understood one particular constructional embodiment thereof will now be described, by way of illustrative example only, with reference to the accompanying drawings in which:

FIG. 1 is a perspective elevational view of an electric time switch embodying the invention;

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FIG. 2 is a part-sectional perspective view of the time switch mechanism included in the device of FIG. 1;

FIG. 3 is a front elevational view of the time switch mechanism shown in FIG. 2;

FIG. 4 is a cross sectional view of the mechanism of FIG. 3, drawn to an enlarged scale and taken, approximately, on the line IV-IV of that figure.

FIGS. 5, 6, 7 and 8 are a series of largely diagrammatic views of the switching elements of the mechanism shown in FIGS. 2-4, illustrating different stages of the on and off switch operations.

Referring first to FIG. 1 of the drawings, the time switch illustrated is one particularly suitable for location on a horizontal surface, such as a table or the floor a'djacent the electrical apparatus to be controlled thereby. The same embodiment is, however, convenient also for wall mounting.

The switch comprises a substantially circular housing 10 of shallow conical outline and a re-entrant conical surfaced central recess 11 surrounding an annular fixed time scale plate 12. The inner margin of the time scale region terminates in an outwardly returned flange 13 around a circular central opening 14 which exposes a setting knob 15 in the form of a moulded disc having four recesses 16 shaped to provide finger pressure walls 17 lying substantially parallel with an extending radially from the central generation axis of the housing and interconnected by sloping surfaces 18 which extend at an angle only slightly displaced from a plane normal to the said generation axis. Such form of knob makes it substantially impossible for an operator to turn the knob 15 anticlockwise and thereby cause possible damage to the mechanism to be described later.

Adjacent the outer end of one of the walls 17 an integral boss 19 carries a setting index 20 for cooperation with a 24-hour time scale 21 carried around the sloping wall of the flange 13. The annular time scale plate 12 carries markings dividing it into 24 sections in alignment with the markings on the time scale 21 and has two concentric circles of holes 22, 23 therethrough for the reception of adjustatble abutment or target pins 24. A storage or parking region 25, comprising a group of holes, is provided on the housing for retaining unused target pins 24.

At the centre of the setting knob 15 is located an override control knob 26 rotatable over a limited arc in either direction for manual over-riding control of the internal time-controlled switch, movement of such knob in clockwise direction causing closure of the switch if otherwise open and reverse movement in anti-clockwise direction causing opening of the switch if otherwase closed. A central aperture in the knob 26 exposes the end of a neon indicator lamp 27 which is energised whenever the controlled switch is closed. A connecting cable 28 to power supply point and to the controlled apparatus extends outwardly either through an aperture at the back of the housing 10 or through an alternative, normally plugged, aperture 29 at the front of such housing.

Referring now to FIG. 2 of the drawings, the plate 12 is formed integrally with a stationary frame 30 'which includes a fixing plate which is square in outline and is provided with securing holes 31 by which it is attached to the underside of the housing 10. The holes 22, 23 in the plate 12 are adapted to receive and frictionally retain the target pins 24, any target pin 24a inserted in one of the holes 22 of the outer circle being arranged to cause a switch on operation whereas any target pin 24b inserted in one of the holes 23 of the inner circle is arranged to cause a switch off operation. Conveniently either 48 or 96 equi-spaced holes are provided in each row, as shown in FIG. 1 or FIGS. 2 and 3 respectively to allow selection of switching at any 15 or 30 minute interval within a 24-hour period.

The setting knob 15 has an integral downwardly extending central sleeve 32 (FIGS. 2 and 4) to the lower end of which is connected a gear wheel 33 through a friction coupling constituted by a spring pressure plate 34 retained by a split ring 35 held in a groove in the sleeve. This gear wheel is in driving connection by means of a gear train (not shown) with a time controlled driving source in the form of a synchronous electric motor M.

- Within the sleeve 32 of the rotatable setting member 15 a tapered sleeve 36 integral with the over-ride control knob 26 is interconnected as by way of a key and slot coupling with an upwardly directed bushing 37 rotatable within the sleeve 32 (FIGS. 2 and 4) and integral with a plate 38 Which carries an arcuate rib 39 thereon to be described later. The neon lamp 27 is located in a holder 40 within the sleeve 36. Connections 41 extend to a terminal board (not shown).

Between the underside of the setting knob 15 and a lower frame plate 42 secured to the lower surface of the frame 30 are two parallel toothed discs 43 and 44 (FIGS. 2 and 4), each arranged to be capable of a limited rocking movement about and journalled on the central sleeve 32 of the setting knob 15.

The lower toothed disc 44 carries a downwardly projecting pin 45 (FIG. 4) extending through an 'arcuate slot 46 in the lower frame plate 42 to a position adjacent a switch operating lever arm 47 which is pivoted at 48 (FIG. 2) on the lower face of the frame plate 42. The disc 44 is biased by a spring as shown at 49 normally to maintain its pin 45 in contact with a fixed stop pin 50 (FIGS. 4, and 6) on the frame plate 42. The lever arm 47 is operative upon the operating plunger 51 of an electric switch 52 which is conveniently of the microswitch type and is also secured to the rear surface of the frame plate 42. This switch is also connected to terminals on the terminal board of the device.

The upper toothed disc 43 carries 'a downwardly projecting pin 53 which extends through an arcuate slot 54 in the toothed disc 44 and an arcuate slot 55 in the lower frame plate 42 to lie adjacent a projection 56 on a latch lever 57 which is pivoted at 58 on the lower face of the frame plate 42. This latch lever has a stepped latching nose 59 for co-operation with the free end 60 of the switch operating lever arm 47. The latch lever 57 is spring biased towards the lever arm 47 by means of a resilient tail 61 which engages with a fixed abutment 62 on the frame plate 42.

A radial projection 63 of the setting knob 15 carries a downwardly directed pivot pin 64 upon which is pivotally mounted an upper or "011? pawl 65 in alignment with the toothed disc 43 and a lower or on pawl 66 in alignment with the toothed disc 44. As shown more clear- 'ly in FIGS. 5 and 6, the on pawl 66 has a resilient tail 67 in engagement with a projection 68 on the underside of the knob 15 whereby the tooth 69 on the pawl is held clear of the toothed periphery of the disc 44 until an upwardly directed detent 70 on the pawl comes into contact with the downwardly projecting end of any target pin 24a inserted in any one of the outer circle of holes 22 in the time scale plate 12. When such engagement occurs the tooth 69 is forced into engagement wtih the toothed disc 44 until the detent 70 is again moved clear of the pin 240.

As shown more clearly on FIGS. 7 and '8, the off pawl 63 is similarly provided with a resilient tail 71 in engagement with a projection 72 on the underside of the knob 15 whereby the tooth 73 on such pawl is normally held clear of the teeth of the toothed disc 43 until a detent 74 on the pawl comes into contact with any downwardly projecting target pin 24b inserted in the inner or off circle of holes 23 in the time scale plate 12. When such contact occurs the tooth 73 is forced into engagement with the disc 23 until the detent 74 is again moved clear of the projecting target pin.

As shown more clearly in FIGS. 5-8, the arcuate rib 39 on the plate 38 which is operable by the manual override knob 26 has one end adjacent a -shoulder"75 on the latch lever 57 and its other end adjacent a corner 76 of the switch operating lever arm 47.

The manner of operation of the time switch is as follows: Assuming target pins 24 have been inserted into the on circle of holes 22 and the off circle of holes 23 at positions corresponding to the desired switch-on and switch-off times, that the time index 19 on the setting knob 15 has been adjusted to accord with local time and that the synchronous motor M is energized, then the setting knob 15 together with the pawls 65, 66 will'be rotated at the speed of one revolution in every 24 hours.

At some later time instant, coincident with the desired switching-on time, the target pin 24a engages the detent 70 on the pawl 66 (see FIG. 5) and, by inward movement of such pawl, causes the tooth 69 to be forced into engagement with the toothed disc 44 (see FIG. 6). In consequence such toothed disc is rotated along with the pawl until the detent 70 rides past the stationary target pin whereupon the pawl moves outwardly again and the tooth 69 is uncoupled from the toothed disc 44. The rocking movement of the disc 44 which thus takes places causes the projecting pin 45 thereon to engage and move the switch operating lever arm 47 in anti-clockwise direction (FIG. 6) to depress the plunger 51 and thereby cause closure of the control switch 52. At the same time the latch lever 57, under the influence of its spring tail 61, moves anti-clockwise to latch the end 60 of the switch lever 47 by its nose 59 so that the switch is held closed even when the pin 45 returns to its normal position after passage of the detent 70 beyond the target pin 24a.

When at the chosen switch-off time, the detent 74 of the pawl 65 engages the inserted target pin 24b (see FIGS. 7 and 8), the pawl is similarly forced inwards to cause its tooth 73 to engage with the toothed disc 43. The latter is accordingly carried round with the pawl until the detent moves clear of the target pin and in doing so causes movement of the latch lever 57 in a clockwise direction by pressure of its pin 53 on the projection 56. This motion causes the nose 59 to be withdrawn from the end 60 of the switch operating lever 47 thereby releasing the switch plunger 51 to return the switch to the open position.

Rotation of the over-ride control knob 26 in a clockwise direction causes the right hand end of the rib 39 (FIGS. 5 and 6) to bear upon and rock the switch operating lever arm 47 into the switch-closed position where it becomes latched by the latch lever 57. Rotation ofthe same knob 26 in an anti-clockwise direction causes the left hand end of the rib 39 (FIGS. 7 and 8) to press upon the shoulder 75 thereby to rock the'latch lever 57 clockwise and so release the lever 47 if this is already held thereby so as to move the switch 52 to the open position.

While one particular constructional form of device has been described in detail it will be obvious to those skilled in the art that numerous modifications may be made without departure from the scope of the invention as defined in the appended claims.

I claim: v

1. An electric time switch including switch means operable to first and second switching positions, and switch operating means comprising first and second spring biased toothed discs adapted for limited rocking movement, first and second pawls, means mounting said pawls for rotation in a path about the circumference of said discs, each of said first and second pawls being adapted to selectively engage an associated toothed disc for effecting rocking movement thereof, and abutments positionable along the path of movement of said pawls and adapted to engage said pawls and cause alternate temporary coupling of said pawls to said discs, whereby said discs will be alternately moved through limited rocking movement to effecteaid first and second switching positions.

2. An electric time switch including switch means operable to first and second switching positions, and switch operating means comprising first and second spring biased toothed discs adapted for limited rocking movement, first and second continuously rotating pawls, each of said first and second pawls being adapted for temporary coupling to an associated one of said first and second discs, a fixed position time scale plate having a series of holes therein disposed along the path of movement of said pawls, and target pins selectively positionable within said holes along the path of movement of said pawls to engage said pawls and cause alternate temporary coupling of said pawls to said discs, whereby said discs will be alternately moved through limited rocking movement to effect said first and second switching positions.

3. An electric time switch according to claim 2 wherein said holes are disposed in two concentric circles in said time scale plate.

4. An electric time switch including switch means operable to first and second switching positions, and switch operating means comprising first and second spring biased toothed discs adapted for limited rocking movement, first and second continuously rotating pawls, each of said first and second pawls being adapted for temporary coupling to an associated one of said first and second discs, abutments positionable along the path of movement of said pawls and adapted to engage said pawls and cause alternate temporary coupling of said pawls to said discs whereby said discs will be alternately moved through limited rocking movement to elfect said first and second switching positions, a switch operating lever arm adapted to operate the switch means through cooperation with the toothed disc associated with said first pawl, a latch lever adapted to latch said lever arm in switch operating relation, said toothed disc associated with said second pawl being adapted to trip said latch lever to thereby release said lever arm from its switch operating position.

5. An electric time switch according to claim 4 including a manual over-ride control means adapted for movement in one direction to move said switch operating lever arm to its operated and latched-in position and for movement in an opposite direction to trip said latch lever to release said switch operating lever arm.

6. An electric time switch according to claim 5 including a continuously rotatable time setting member and means for rotating said member at a uniform speed through a friction drive clutch, said first and second pawls being mounted on said time setting member, and said first and second toothed discs being journalled concentrically with said time setting member.

7. An electric time switch according to claim 6 wherein said time setting member includes a central bore therein, and wherein said manual over-ride control comprises a rotatable member located within said central bore.

8. An electric time switch according to claim 7 including an indicator lamp mounted in said over-ride control.

9. An electric time switch according to claim 6 wherein said time setting member includes finger grip surfaces adapted to prevent manual rotation in one direction.

10. An electric time switch including switch means operable to first and second switching positions, and switch operating means comprising toothed disc means adapted for limited rocking movement, pawl means, means mounting said pawl means for rotation in a path about the circumference of said disc means, said pawl means being adapted for selective temporary coupling to said disc means, and abutment means positionable along the path of movement of said pawl means and adapted to cause temporary coupling of said pawl means to said disc means whereby said disc means will effect said first and second switching positions.

References Cited UNITED STATES PATENTS 1,003,335 9/1911 Carpenter 200-35 2,048,742 7/1936 Horelick 20037 2,294,961 9/1942 Carlson et a1. 200-38 2,780,754 2/1957 Lovell 335l40 BERNARD A. GILHEANY, Primary Examiner.

R. L. COHRS, Assistant Examiner. 

